offset shackles (how big a tire)

Rolling the inner fenders will get you a little more room as well. I have all ready rolled mine. Next is the offset spring kit. I don't know yet but I think with the two you may get a 10" tire in there. Or at least close. I won't know till I get both done and brake out the tape. My plan was to go with some 15x8's centered up in the well then cram as much rubber in there as I can with out it rubbing.

Good luck.